P T Chambers wrote:
>
> I see there are 2 interpretations of the question. One set
> thinks that Mark wanted to measure how big his pupil gets.
>
> The other set thinks that he wanted to measure the actual
> -exit pupil- of an EP/Scope combination.
Of course. I decided to take him literally and discuss the
telescope's exit pupil first.
BTW, the caliper method can be used with a scope or eyepiece of
unknown focal length or magnification. The clear aperture can usually
be measured, then the magnification calculated. Or if the primary
properties are known, one can calculate the mag and then the focal
length of the eyepiece.
-- Jim Van Nuland, San Jose (California) Astronomical Association <a href="http://www.svpal.org/~jvn/ ">JVN's home page</a>Received on Tue Jul 27 14:43:41 2004